Speakers of such a type are generally known; e.g. PCT Patent Application WO 96/14722 discloses such a loudspeaker. This known loudspeaker has a frame, a membrane and an electromagnetic driving unit. The membrane is formed by a conical body and has an outer circumferential edge and an inner circumferential edge. The driving unit is provided with a stationary part and a movable part. The stationary part includes a permanent magnet and a magnetic yoke and is secured to the frame. The movable part includes a voice coil and a cylindrical coil support. At its outer circumferential edge, the membrane is connected to the frame by means of a flexible suspension and, at its inner circumferential edge, it is adhered to the coil support, which in its turn is connected to the frame by means of a spider.
The conical membrane of the known loudspeaker has a certain height in order to obtain sufficient stiffness. The membrane must have a certain minimal stiffness in order to be able to move like a piston, not only for low frequency reproduction but for the whole or at least the larger part of the audio spectrum.
For this reason, there arise problems relating to the speaker's performance when a shallow speaker, i.e. a speaker having a small height, is required in certain applications.
It is an object of the invention to improve the known loudspeaker in such a way that it can be given a small height without degrading its sound performance.